Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K49/00—Dynamo-electric clutches; Dynamo-electric brakes
  • H02K49/10—Dynamo-electric clutches; Dynamo-electric brakes of the permanent-magnet type
  • H02K49/102—Magnetic gearings, i.e. assembly of gears, linear or rotary, by which motion is magnetically transferred without physical contact
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B3/00—Rotary drilling
  • E21B3/02—Surface drives for rotary drilling
  • E21B3/04—Rotary tables
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D9/00—Adaptations of wind motors for special use; Combinations of wind motors with apparatus driven thereby; Wind motors specially adapted for installation in particular locations
  • F03D9/20—Wind motors characterised by the driven apparatus
  • F03D9/25—Wind motors characterised by the driven apparatus the apparatus being an electrical generator
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
  • F16H1/32—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
  • E21B19/008—Winding units, specially adapted for drilling operations
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2220/00—Application
  • F05B2220/70—Application in combination with
  • F05B2220/706—Application in combination with an electrical generator
  • F05B2220/7068—Application in combination with an electrical generator equipped with permanent magnets
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H49/00—Other gearings
  • F16H49/001—Wave gearings, e.g. harmonic drive transmissions

Definitions

• the present disclosure relates to radial magnetic cycloid gear assemblies, and related systems and methods for rotary drives, including for example, for use in various rotary driven industrial equipment, such as, for example, ship engines, wind turbine nacelles, and various oil rigging equipment.
• Gearboxes and gear arrangements are utilized in a wide range of applications in order to provide speed and torque conversions from a rotating power source to another device.
• gearboxes have been formed from gear rings, or wheels, each being sized and having a number of teeth selected to provide a desired gear ratio, which in turn affects the torque ratio.
• Such mechanical gearboxes may produce relatively large acoustic noise and vibration.
• the mechanical components of gearboxes are subject to wear and fatigue (e.g., tooth failure), and require periodic lubrication and maintenance.
• mechanical gear arrangements can have inefficiencies as a result of contact friction losses.
• Magnetic gear arrangements have been developed as a substitute for mechanical gear arrangements.
• Some magnetic gears are planetary in their arrangement and comprise respective concentric gear rings with interpoles positioned between the gear rings.
• the rings incorporate permanent magnets, and the interpoles act to modulate (shutter) the magnetic flux transferred between the permanent magnets of the gear rings. In this manner, there is no mechanical contact between the gear rings or the input and output shafts of the gearbox.
• utilizing such magnetic gear arrangements may alleviate many of the noise and wear issues associated with mechanical gears that rely on intermeshing teeth.
• Some such gears include harmonic gears that utilize a flexible, thin-walled toothed spline structure that moves within and intermeshes with a fixed outer toothed spline; the latter structure sometimes being referred to as a skin.
• a wave generator may be attached to an input shaft that is rotated within the flexible spline to rotate the flexible spline around and within the outer fixed spline, with the flexible inner spline being attached to an output shaft.
• Mechanical harmonic gears generally are characterized by relatively high gear ratios and minimal backlash, which is the error in motion that occurs based on the size of the gap between the leading face of the tooth on the driven gear and the trailing face on the tooth of the driving gear.
• the flexible spline structures of mechanical harmonic gears are a relatively weak structural component that limits the output torque of such gears, thus providing relatively low output torques.
• an inner rotor gear ring supports an array of magnets and an outer stator gear ring supports an array of magnets.
• the number of magnets on the inner and outer gear rings differ, and the inner rotor gear ring axis is offset from the outer stator gear ring axis.
• the inner rotor gear ring is allowed to also freely rotate about its own axis as it is driven by a drive shaft aligned with the outer stator gear ring axis.
• the nearest magnets between the inner and outer gear rings have the strongest attraction.
• a magnetic cycloid gear assembly may include an outer magnet drum comprising a plurality of outer drum magnets having a first number of magnetic pole pairs.
• the outer magnet drum may have an outer magnet drum axis.
• the assembly may also include a first inner magnet drum comprising a first plurality of inner drum magnets having a second number of magnetic pole pairs.
• the first inner magnet drum may have a first inner magnet drum axis that is offset from the outer magnet drum axis.
• the assembly may also include a second inner magnet drum comprising a second plurality of inner drum magnets having a third number of magnetic pole pairs.
• the second inner magnet drum may have a second inner magnet drum axis that is offset from the outer magnet drum axis.
• the outer magnet drum may surround the inner magnet drums.
• the assembly may further include a plurality of drive mechanisms, each drive mechanism being operatively coupled to each of the first and second inner magnet drums.
• the plurality of drive mechanisms may be configured to drive each of the first and second inner magnet drums to revolve in an eccentric manner about the outer drum axis.
• the outer magnet drum may be configured to rotate about the outer magnet drum axis in response to the revolution of the first and second inner magnet drums.
• a method of torque conversion may include revolving first and second inner magnet drums within an outer magnet drum in an eccentric manner about an axis of rotation of the outer magnet drum.
• Each of the first and second inner magnet drums may include a first plurality of magnets having a first number of pole pairs and the outer magnet drum comprises a second plurality of magnets having a second number of pole pairs that differs from the first number of pole pairs.
• the revolving may be provided by a plurality of drive mechanisms each configured to provide a high speed, low torque input.
• the method may further include, in response to the revolving of the inner magnet drums, causing the outer magnet drum to rotate about the outer magnet drum axis of rotation to provide a low speed, high torque output.
• FIGS. 1 A and 1 B are schematic perspective and plan views, respectively, of a conventional magnetic cycloid gear
• FIGS. 2A and 2B are schematic plan and partial detailed views, respectively, of an exemplary magnetic cycloid gear arrangement illustrating principles of operation in accordance with the present disclosure
• FIG. 3 is a perspective view of an exemplary embodiment of a magnetic cycloid gear assembly for use with a top drive in accordance with the present disclosure
• FIG. 4 is a perspective, cross-sectional view of the assembly of FIG. 3 taken along line 4-4 in FIG. 3, with a support structure removed to better shown the internal components of the assembly;
• FIG. 5 is an exploded perspective view of the assembly of FIG. 3, with the support structure removed to show the assembly's drive mechanisms;
• FIG. 6 is a diagrammatic cross-sectional view of the assembly of FIG. 3 taken along line 4-4 in FIG. 3, including the support structure;
• FIG. 7 is an exploded perspective view of the assembly of FIG. 3, including the support structure;
• FIG. 8 is a perspective view of an exemplary embodiment of an inner magnet drum in accordance with the present teachings.
• FIG. 9 is a perspective view of an exemplary embodiment of a support structure in accordance with the present disclosure, with drive mechanisms positioned therein;
• FIGS. 10A and 10B are partial, perspective views of the support structure of FIG. 9, respectively showing eccentric cams at opposite ends of each drive mechanism;
• FIG. 1 1 is another perspective view of the support structure of FIG. 9, showing an exemplary embodiment of a s-shaped shaft in accordance with the present disclosure
• FIG. 12 is an enlarged, perspective view of the s-shaped shaft of FIG. 1 1 ;
• FIG. 13 is a perspective view of an exemplary embodiment of a bearing end plate in accordance with the present disclosure.
• FIG. 14 is a another perspective view of the support structure of FIG. 9 with the bearing end plates attached thereto;
• FIG. 15 is a perspective view of another exemplary embodiment of a magnetic cycloid gear assembly for use with a top drive in accordance with the present disclosure
• FIG. 16 is a schematic view of an exemplary oil drilling rig system with which magnetic cycloid gear assemblies in accordance with various exemplary embodiments of the present disclosure may be used to drive rotary equipment of the system;
• FIG. 17 is a diagrammatic perspective view of a top drive with an integrated magnetic cycloid gear and motor drive assembly in accordance with various exemplary embodiments of the present disclosure;
• FIG. 18 is a partial, schematic view of an exemplary windmill with which magnetic cycloid gear assemblies in accordance with various exemplary embodiments of the present disclosure may be used to generate electricity;
• FIGS. 19A-19D show schematic representations of relative motion of an inner magnetic gear ring and an outer magnetic gear ring in accordance with various exemplary embodiments
• FIG. 20 is an exploded perspective view of another exemplary embodiment in accordance with the present disclosure.
• FIG. 21 is a diagrammatic cross-sectional view of yet another exemplary embodiment in accordance with the present disclosure.
• magnetic cycloid gear arrangements can provide improved performance (e.g., gear ratios and output torque densities) with less magnet volume than various other magnetic gear configurations.
• various exemplary embodiments of magnetic cycloid gears described herein may achieve gear ratios of at least 15:1 , for example in the range of from 15:1 to 75:1 .
• the magnetic cycloid gears can be sized to achieve a torque output sufficient for driving various rotary equipment and turbine engines where high torque density drive is desirable.
• Non-limiting examples of application of the gears of the present disclosure include a top drive in an oil drilling rig, a nacelle tower of a wind turbine, a drive train of a ship.
• the torque achievable ranges from 0 to full rating.
• a magnetic cycloid gear arrangement that achieves such torque outputs may be about 26 in. in height and about 24 in. in diameter.
• the torque input required to drive the gear rotor only has to deliver 1 /30-1 /31 of the torque, and thus may be relatively small.
• the gear arrangements in accordance with various exemplary embodiments may utilize relatively small motors that can be placed in relatively small and/or confined spaces associated with the gear, such as, for example, inside the gear's inner magnet drums. This may permit providing gear arrangements that are relatively compact.
• magnetic cycloid gear assemblies in accordance with the present disclosure may be useful to deliver torque to drive a variety of rotary equipment, including but not limited to, for example rotary equipment in oil drilling systems.
• the use of such magnetic cycloid gear assemblies in accordance with the present disclosure in oil drilling systems and other applications may be desirable as the arrangements can be relatively compact in design, with relatively few components that deliver high torque in an integrated motor/gear system.
• the use of magnetic gearing can reduce vibrations, acoustic issues, and wear that are associated with conventional mechanical (e.g., toothed) gear systems.
• by reducing the number of contacting mechanical parts friction losses and potential damage due to harsh environments, as are sometimes associated with oil drilling rigs and other industrial applications, can be mitigated using magnetic gearing arrangements.
• FIG. 16 illustrates a schematic diagram depicting an oil drilling rig 2900 for which the magnetic cycloid gear assemblies in accordance with various exemplary embodiments may be used in accordance with aspects of the present disclosure.
• the rig 2900 includes a derrick 2902 from which extends a drill string 2904 into the earth 2906.
• the drill string 2904 can include drill pipes and drill collars.
• a drill bit 2912 is at the end of the drill string 2904.
• a rotary system 2914, top drive 2926, and/or a downhole drive 2932 may be used to rotate the drill string 2904 and the drill bit 2912.
• the top drive 2926 is supported under a travelling block 2940, which can travel up and down in the derrick 2902.
• a draw works 2916 has a cable or guy wire apparatus 2918 for raising and lowering the drill string 2904.
• a system 2922 with one, two, or more mud pump systems 2921 supplies drilling fluid 2924 using hose 2944 to the drill string 2904, which passes through the center of the top drive 2926. Drilling forms a wellbore 2930 extending down into the earth 2906.
• the drilling fluid 2924 is pumped by mud pump(s) 2921 of the system 2922 into the drill string 2904 passing through the top drive 2926 (thereby operating a downhole drive 2932 if such is used).
• Drilling fluid 2924 flows to the drill bit 2912, and then flows into the wellbore 2930 through passages in the drill bit 2912. Circulation of the drilling fluid 2924 transports earth and/or rock cuttings, debris, etc. from the bottom of the wellbore 2930 to the surface through an annulus 2927 between a well wall of the wellbore 2930 and the drill string 2904.
• the cuttings are removed from the drilling fluid 2924 so that the fluid may be recirculated from a mud pit or container 2928 by the pump(s) of the system 2922 back to the drill string 2904.
• the rotary equipment such as top drive 2926, draw works 2916, mud pumps 2921 , may be driven by motors and one or more magnetic cycloid gear assemblies in accordance with exemplary embodiments herein, which can provide a large torque at a low speed.
• FIG. 17 illustrates one exemplary embodiment of a top drive 2926 with an integrated magnetic cycloid gear and motor drive assembly 1700 in accordance with various exemplary embodiments, as will be described further below (see, e.g., FIGS. 3-14).
• Other parts of the top drive include a swivel house 1740 and main shaft 1760.
• the magnetic cycloid gear and drive assembly 1700 may have a passage 1735 there through (e.g., like mud pipes described in further detail below).
• the output of the drive may be of high torque and slow speed in an industrial scale, or varied torque/speed characteristics.
• Magnetic Cycloid Gears may be of high torque and slow speed in an industrial scale, or varied torque/speed characteristics.
• FIGS. 1 A and 1 B operation of conventional magnetic cycloid gears will now be described.
• a rotor axis A r is displaced with respect to a stator axis A s (e.g., to the right in the view and position of the gear rings in FIGS. 1 A and 1 B).
• inner and outer gear rings 120 and 1 10 are positioned in a non-concentric manner such that their respective axes A n and A s are not aligned.
• the inner gear ring 120 or the outer gear ring 1 10 is allowed to move as a whole such that its axis traces a small orbital path (e.g., revolves)
• magnets carried by the inner and outer gear rings 120, 1 10 will be in closest proximity at various angular positions during the revolving.
• the inner ring 120 is allowed to also rotate about its axis A r while it revolves (orbits) around the outer gear ring 1 10 axis as the outer gear ring 1 10 is held stationary, a gear ratio is produced.
• the inner gear ring 120 is held stationary and the outer gear ring 1 10 is allowed to revolve as described above, while also rotating about its own axis A s , another gear ratio is produced.
• the inner gear ring 120 may be driven by an eccentric input drive shaft 150 that is aligned with the outer gear ring 1 10 axis A s at its input rotation axis and is fixed at its other end to the inner gear ring axis A r .
• the input drive shaft 150 is rotated (i.e., about the axis A s )
• the end of the input shaft 150 that is fixed at the axis A r (and thus the position of A r ) traces out the trajectory T shown in the dashed lines of FIG. 1 B.
• FIGS. 19A-19D schematically depict the motion of an inner gear ring 120B revolving (orbiting) around the axis of rotation a of outer gear ring 1 10A.
• inner gear ring 120B revolves around axis a such that the axis b of inner gear ring 120B moves along path B.
• FIGS. 19A-19D schematically depict the motion of an inner gear ring 120B revolving (orbiting) around the axis of rotation a of outer gear ring 1 10A.
• the inner gear ring 120B is prevented from rotating about its axis b during the revolution around axis a and accordingly the orientation of inner gear ring 120B does not change, as depicted by the arrow being oriented in the same direction in each of FIGS. 19A- 19D.
• FIGS. 2A and 2B show schematic plan and partial detailed views of another exemplary magnetic cycloid gear arrangement 200 that includes inner and outer gear rings 220, 210 carrying magnets 221 , 21 1 arranged in a partial Halbach arrangement with 30 pole pairs (60 magnetic poles) on the inner gear ring 220 and 31 pole pairs (62 magnetic poles) on the outer gear ring 210. Because they are arranged in a Halbach array with tangential magnets, the number of magnets for the inner and outer rings 220, 210 is 120 and 124, respectively. In FIGS. 2A and 2B, two blocks represent one magnet pole and four blocks represents one magnet pole pair.
• the radius of the inner gear ring 220 may be 5/8" smaller than the outer gear ring 1 10 and its center displaced 0.5 in. horizontally (to the right in the position and orientation of FIG. 2A).
• the inner gear ring 220 when the inner gear ring 220 is coupled to an input shaft to rotate such that its axis A r traces the dashed line T, the inner gear ring 220 also can undergo a relatively slow rotation in the same direction about its own axis A r equal to a revolution of -2/60 * 360 ° for one complete revolution of the axis A r of the inner gear ring 220 about the trajectory T.
• This rotation about A r results from the coupling between the magnets 221 and 21 1 in light of the differential pole pairs between the two rings 220, 210.
• various magnetic gear arrangements also prohibit the free rotation of one of the gear rings 210, 220 around its own axis, such as for example prohibiting the free rotation of the inner gear ring 220 around its axis A r , while permitting it to revolve such that its axis traces out a small inner orbital trajectory [e.g., T in FIG. 2A).
• gear arrangements contemplate permitting the other of the gear rings to rotate freely about its own axis in response to the magnetic coupling caused by the motion of the inner gear ring 220.
• the outer gear ring 210 may be permitted to rotate freely around its axis A s in response to movement of the inner gear ring 220.
• the outer ring 210 may therefore rotate in the same direction 2/62 * 360 ° for every complete revolution of the axis A r of the inner gear ring 220 about the trajectory T.
• Such a gear arrangement can achieve a gear ratio of about 61 :2 or 30.5:1 , or about 31 :1 .
• Various exemplary embodiments of the present disclosure contemplate utilizing the above magnetic cycloid gear arrangements in assemblies which integrate such gears with a plurality of drive mechanisms, such as, for example, motors or generators.
• a high torque density motor for use with a top drive may incorporate such magnetic cycloid gear assemblies.
• such assemblies may generally achieve a high torque density compared with other types of magnetic gears, this torque advantage may pose other issues.
• counterweights are used to balance the inner drum during its wobble motion.
• FIG. 20 an exemplary embodiment of a magnetic cycloid gear assembly 500 that uses one inner magnet drum 502 and a counterweight 505 is shown.
• the counterweight 505 may be attached to the rotor of the drive motor (not shown) to compensate for the material offset of the inner magnet drum 502 with respect to the primary rotation axis (i.e., during the wobble). In this manner, the counterweight 505 may bring the center of mass of the assembly 500 back to the primary rotation axis.
• the present disclosure further contemplates overcoming such issues with a uniquely designed magnetic cycloid gear assembly that: (1 ) utilizes a plurality of inner drums, which are positioned to offset each other's eccentric motion, and/or (2) distributes the magnetic load among a plurality of drive mechanisms.
• a uniquely designed magnetic cycloid gear assembly that: (1 ) utilizes a plurality of inner drums, which are positioned to offset each other's eccentric motion, and/or (2) distributes the magnetic load among a plurality of drive mechanisms.
• magnetic cycloid gear assemblies in accordance with the present disclosure may be balanced mechanically, thereby eliminating the use of a counterweight.
• the assembly 300 includes first and second inner magnet drums 302 and 304 (or first and second inner gear rings), and an outer magnet drum 306 (or outer gear ring) that surrounds the inner magnet drums 302, 304.
• first and second inner magnet drums 302, 304 are disposed in an end-to-end arrangement within the outer magnet drum 306.
• the outer magnet drum 306 includes a plurality of outer drum magnets 308 having a first number of magnetic pole pairs and an outer drum axis A s (see FIG. 2A).
• the first inner magnet drum 302 includes a first plurality of inner drum magnets 310 having a second number of magnetic pole pairs and a first inner magnet drum axis A r (see FIG. 2A) that is offset from the outer drum axis A s .
• the second inner magnet drum 304 includes a second plurality of inner drum magnets 312 having a third number of magnetic pole pairs and a second inner magnet drum axis A r (see FIG. 2A) that is offset from the outer magnet drum axis A s .
• the pole pair difference between the pole pairs of the outer magnet drum 306 and the respective pole pairs of the two inner magnet drums 302, 304 is about 1 .
• the outer drum magnets 308 may have 31 pole pairs and each of the inner drum magnets 310, 312 may have 30 pole pairs.
• the magnetic cycloid gear assembly 300 also includes a plurality of drive mechanisms 314 (three drive mechanisms 314 being shown in the exemplary embodiment of FIG. 5), wherein each drive mechanism is operatively coupled to each of the first and second inner magnet drums 302, 304 to drive each of the first and second inner magnet drums 302, 304 to revolve in an eccentric manner about the outer drum axis A s (e.g. about the trajectory T in a manner similar to that depicted in FIG. 2A).
• Each drive mechanism includes a shaft 316 that is configured to rotate and to support each of the inner magnet drums 302, 304.
• the shafts 316 are configured to rotate synchronously with each other to drive each of the first and second inner magnet drums 302, 304.
• Each drive mechanism 314 further includes at least one eccentric cam 318 coupled to the drive shaft 316.
• each drive mechanism 314 may include two eccentric cams 318, respectively coupled to opposite ends of the drive mechanism 314. In this manner, as will be described further below, during revolution about the outer drum axis A s , the first and second inner magnet drums 302, 304 may be about 180 0 out of phase with each other during their orbital revolution within the outer drum magnet in order help balance the eccentric motion of the inner drums 302, 304.
• the configuration of the assembly 300 allows each of the inner magnet drums 302, 304 to move as a whole such that each drum's respective axis A r revolves to trace a path along the dashed line T, while also preventing each of the inner magnet drums 302, 304 from rotating about its own axis A n in a manner similar to that described above with reference to FIGS. 19A-19D.
• the inner magnet drums 302, 304 undergo a wobble effect (eccentric motion) such that their respective axes trace an orbital path along the dashed line T, but those same three shafts 316 also prevent each of the inner magnet drums 302, 304 from rotating about its own respective axis.
• the outer magnet drum 306 is allowed to freely rotate about its axis A s in response to the revolution of the first and second inner magnet drums 302, 304.
• each of the drive mechanisms 314 may provide a high speed, low torque input (i.e., to drive the inner magnet drums 302, 304), and the resultant rotary motion of the outer magnet drum 306 may provide a low speed, high torque output (e.g., to drive a mud pipe 380 or other rotary device connected to the outer magnet drum 306).
• the outer drum magnets 308 are arranged in a partial Halbach arrangement having 31 pole pairs and each of the inner drum magnets 310, 312 are arranged in a partial Halbach arrangement having 30 pole pairs, in one full revolution of each of the first and second inner magnet drum axes A r about the dashed line trajectory T, the outer magnet drum 306 rotates 360/31 ° in the same direction as the inner magnet drums 302, 304, thereby resulting in a gear ratio of 31 :1 .
• outer and inner magnet drums 306 and 302, 304 may having various numbers and arrangements of respective outer and inner drum magnets 308 and 310, 312, each having various numbers of magnetic pole pairs to provide various gear ratios without departing from the present disclosure and claims.
• the input torques and speeds provided by the drive mechanisms may be varied based on the number of drive mechanisms employed, the gear ratio of the magnet drums, and the required output of the assembly.
• the plurality of drive mechanisms 314 may include three permanent magnet motors, each including rotor magnets 320 and a stator 322 having end windings (not shown).
• the motors may be surface permanent magnet motors, and in various additional exemplary embodiments (not shown), the motors may be interior permanent magnet motors.
• the first and second inner magnet drums 302, 304 are disposed in an end-to-end arrangement within the outer magnet drum 306, such that respective inner ends 303 and 305 of the first and second inner magnet drums 302, 304 are positioned adjacent to one another.
• an inner drum cavity 324 is defined between opposite outer ends 301 and 307 of the first and second inner magnet drums 302, 304, and the permanent magnet motors 314 are positioned within the inner drum cavity 324.
• each permanent magnet motor drive mechanism 314 has two eccentric cams 318 attached to opposite ends of the rotor shaft 316 of each motor to operatively couple the shaft 316 to the inner magnet drums 302, 304 via, for example, an inner magnetic drum bearing 326.
• the respective outer ends 301 , 307 of the inner magnet drums 302, 304 are positioned on the set of cams 318, and the respective inner ends 303, 305 are positioned on a set of s-shaped shafts as described below.
• each of the cams 318 is offset by an appropriate distance D to create the eccentric (e.g., wobble) motion of the inner magnet drums 302, 304.
• the offset distance D may be optimized using the procedure described in International Publication No. WO 2014/158968 A1 , which is incorporated by reference herein.
• the eccentric cams 318 of each rotor shaft 316 are also offset from one another by about 180°.
• the cams 318 of the first set 318a of cams 318 are offset from the cams 318 of the second set 318b of cams 318.
• the first and second inner magnet drums 302, 304 are about 180° out of phase with each other to help balance the inner drums 302, 304.
• such a configuration of inner magnet drums may mechanically balance the assembly 300, thereby eliminating the need for a counterweight.
• a counterweight within the assembly 300 to help remove secondary vibrations from the assembly 300.
• a counterweight may be added, for example, to an end of one or more of the rotor shafts 316.
• the permanent magnet motors 314 and cams 318 shown in FIGS. 4, 10A, 10B, 1 1 , and 14 are a nonlimiting and exemplary mechanism for revolving the inner magnet drums in an eccentric manner about the outer drum axis A s and other mechanisms may be suitable for achieving the desired revolutionary motion.
• an alternative mechanism for achieving the revolutionary motion includes using a central motor drive in conjunction with orbital gears to achieve the eccentric wobble revolution motion of the inner magnet drums.
• the assembly 300 further includes a support structure 350 positioned within the inner drum cavity 324.
• the support structure 350 may include, for example, a frame structure having a hub and spoke transverse cross-sectional shape along its length. Emanating from a central hub 353 and three hollowed spokes 354, each being configured to receive one of the motors 314.
• a high thermal conductivity, low electrical encapsulate may be disposed inside each hollow spoke 354 to surround each motor 314. As best shown perhaps in FIGS.
• the support structure 350 may further include at least one s-shaped shaft 356 (three s-shaped shafts 356 being utilized in the embodiment of FIGS. 3-14, although only one shaft 356 is shown in the views of FIGS. 1 1 and 14) to receive and support adjacent ends 303, 305 of the inner magnet drums 302, 304 when the inner drums are in the end-to-end arrangement within the outer magnet drum 306.
• the s-shaped shaft 356 may provide a center based support for each of the inner magnet drums, which would otherwise be cantilevered without such support.
• the support structure 350 has a cutout portion 358 every 120 ° to separate the spokes 354.
• An s-shaped shaft 356 is positioned within each of the three cutout portions 358, are disposed in each cutout portion 358 to receive and support each shaft 356.
• the support structure 350 may also be fitted with bearings, such as, for example, inner magnet drum bearings 326 and motor bearings 328 to operatively couple each motor 314 held within the spokes 354 of the support structure 350 to each of the inner magnet drums 302, 304.
• each inner magnet drum 302, 304 may include a set of flanges 31 1 to engage the s- shaped shafts 356 and a set of flanges 309 to engage the inner magnet drum bearings 326 (which are positioned over the cams 318).
• the outer ends 301 , 307 and inner ends 303, 305 of the inner magnet drums 302, 304 are operatively coupled to and supported by the respective bearings 309 and 31 1 of the support structure 350.
• the ends of the support structure 350 may be covered with caps 330 (see FIG. 14).
• the assembly 300 also can include a pair of bearing end plates 360, with one bearing end plate 360 being affixed to each end of the support structure 350.
• the bearing end plates 360 may, for example, each have openings 362 to allow water and/or oil to be brought into the support structure 350 to cool the motors 314.
• the assembly may also include a pair of drum end plates 370.
• the drum end plates 370 may, for example, be positioned at each end of the assembly 300 and include a plurality of stabilizing legs 372.
• each drum end plate 370 has three stabilizing legs 372, and each stabilizing leg 372 is configured to fit into a cutout portion 358 of the support structure 350 to engage the s-shaped shaft positioned within the cutout portion 358 (see FIG. 4) .
• each stabilizing leg 372 is configured to fit into a cutout portion 358 of the support structure 350 to engage the s-shaped shaft positioned within the cutout portion 358 (see FIG. 4) .
• magnetic cycloid gear assemblies in accordance with the present disclosure may have various components in various arrangements, including for example, various numbers, types and/or configurations of inner magnetic drums, bearings, cams, support structures, and/or end plates, without departing from the scope of the present disclosure and claims.
• a magnetic cycloid gear assembly 600 may include three inner magnet drums 602 (or three inner gear rings). Similar to the assembly 300, the inner magnet drums 602 are disposed in an end-to-end arrangement within the outer magnet drum (not shown) and are driven by a plurality of permanent magnet motor drive mechanisms 614 (only one drive mechanism being shown in the view of FIG. 21 ).
• Each permanent magnet motor drive mechanism 614 has asymmetric cams 618, with eccentric lobes and bearings (e.g., similar to a crankshaft in an engine), attached to opposite ends of a rotor shaft 616 of each motor to operatively couple the shaft 616 to the inner magnet drums 602. Similar to the embodiment of FIG. 20, various additional embodiments also contemplate using a counterweight (not shown) to help balance the assembly 600.
• the drive mechanisms e.g., permanent magnet motors 314.
• the drive mechanism may be positioned external to the magnet drums.
• a magnetic cycloid gear assembly 400 may include permanent magnet motors 414 that are positioned and supported outside the inner drum cavity (not shown).
• the motors 414 may be positioned external to both the outer magnetic drum 406 and the inner magnet drums (inner magnet drum 404 being the only inner drum shown in FIG. 15), such as, for example, adjacent to the magnet drums.
• an eccentric input drive crank shaft drive driven by an external motor or generator may be used to drive the inner magnet drums of a magnetic cycloid gear assembly in the desired motion.
• the gear ratios that can be achieved by such assemblies are so high, e.g., on the order of about 31 :1 or more, the torque required to drive the gear need only deliver about 1/31 or less of the desired output torque.
• various exemplary embodiments contemplate using a magnetic cycloid gear assembly, such as, for example, the assembly 300 to drive rotary equipment associated with oil drilling rigs, such as, for example, drawworks, mud pumps, and/or top drives, as described with reference to FIG. 16 and disclosed for example in
• FIGS. 3, 4, and 6, illustrate the assembly 300 for use in driving a top drive mechanism of an oil drilling rig, wherein 380 represents the pipe (such as pipe 2904 in FIG. 16) of the top drive that carries mud in the direction of the arrow.
• FIGS. 3, 4, and 6 show only one representation of how a magnetic cycloid gear assembly in accordance with the present disclosure can be used with a top drive of an oil drilling rig, and in particular by relying on relatively small onboard permanent magnet motors 314 to drive the inner magnet drums 302, 304.
• the permanent magnet motors 314 can be operatively coupled and disposed to directly drive the inner magnet drums 302, 304 to revolve the drums to trace a path along the dashed line T. And, by virtue of the magnetic coupling with the inner magnetic drums 302, 304, the outer magnetic drum 306, which is coupled to the pipe 380, is allowed to freely rotate about its axis A s in response to the revolution of the first and second inner drum magnets 302, 304. In this manner, each of the motors 314 may provide a high speed, low torque input to drive the inner magnet drums 302, 304, and the resultant rotary motion of the outer magnet drum 306 may provide a low speed, high torque output to the pipe 380.
• the torque demand T input under the exemplary top drive i.e., the combined input torque of the motors
• the desired torque output Toutput divided by the gear ratio would be:
• each of the motors 314 must provide 1 /3 of this input torque, or about 290 ft-lbs per motor.
• a maximum continuous torque ranging from about 20,000 ft-lbs to about 35,000 ft-lbs, such as, for example, 25,000 ft-lbs to about 29,000 ft-lbs, at a speed ranging from about 100 rpms to 145 rpms, with a maximum speed ranging from about 200 rpm (revolutions per minute) to about 225 rpm, and a torque density ranging from about 1 .5 ft-lb/in 3 to about 2.6 ft-lb/in 3 . It is contemplated that relatively compact arrangements can be used to deliver these specifications, for example, ranging from about 24 in. to about 28 in.
• the mud flow can be considered as a mechanism for cooling the stator.
• induction motors it may be desirable to provide a blower for cooling the rotor.
• a windmill 3000 may include a magnetic cycloid gear assembly 3300, which includes generators (instead of motors), such as, for example, three permanent magnet generators 3314.
• generators instead of motors
• blades 3375 of the windmill 3000 may be coupled to a main shaft 3380, which in turn may drive the permanent magnet or induction generators 3314 to generate power via an inverter 3390.

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• 2015
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